So living with an XF has been cool so far, although I do have a belt change coming up this year. I have the engine timing kit, I just have to find the enthusiasm, the better weather and no back pain to do it..or just let someone else do it?

I had just started the car the other night and reached a mile up the road when "BHAM!!!!" The red waring lamp of despair light up on the instrument cluster "Reduce engine performance"! Oh B#LL##KS came out of my mouth, I was sure that as soon as that light came on that I did indeed have restricted performance! Anyhow, I drove another couple of miles and went into a shop, came out and started the engine, light still on but sounded fine. I thought to myself "this warning lamp is going to drive me nuts", unlike a little engine management lamp being on, the big red illuminated message is like the car is mocking you (I am your Jaguar and I am broken and I am not going to tell you why I am sick....I am just going to nag you until you do something)!!!! So I hit the clear message button and it hasn't come on since and it drives fine.

I am considering that the car had a brain fart...maybe the rain got in where it doesn't like it, a temp injector fault or a sticky actuator. When I bought the car I also bought a copy and modified mongoose lead and a tamed copy of SDD software, it has only taken me 7 months to create a virtual xp computer on my laptop and install it.... My view now is to get a simple fult code puller and try that first, then if there is a fault still present use the SDD to help eliminate and rectify it. I am waiting for a icarsoft unit to turn up (it is supposed to be able to access body modules as well as generic fault codes, but we will see?). I did buy a Vgate scan android reader...I found it was junk...tried torque, it would not connect properly and a load of other apps.

So, wait and see...I will let you know when I have sussed it out!

 

Weak batteries cause all sorts of electrical glitches.

 

Yep, if you're still on the original battery after over five years there is a good chance it's now on the way out and was the root cause of the brain fart.

 

Thanks guys, although I am not sure if I have a battery fault. I haven't tested it yet but the car starts on the button with plenty of cranking speed. When my diagnostic equipment turns up I will see if anything is logged on the ECU. Mind you, I do have a battery drop tester but thinking about it...I would be better of scanning the car first before I disconnect the battery.

 

Well I scanned the car today and pulled one non relevant fault code, so I shall now do a drop test on the battery.

 

I gotten the restricted performance message about 4 or 5 times since I've owned the car. Only once was there a real restricted performance issue - car felt like the brakes were on. This was also cleared after restarting the car. Every other time I've gotten the message car runs fine and it goes away on its own and before I can get the car to the dealer. I've read the code while the restricted performance and MIL light were on and got the p0018 code. -I believe its the crankcase position sensor failure. Told the dealer and they found the sensor loose so they cleaned and re-torqued the sensor. It's happened once again after that - brought it back but they couldn't find a fault (the warning and code in the MIL disappeared again!!!). I heard this could also be caused by timing chain issues (cam and crank getting out of sync) but hopefully I'm good there. Car has been running great for a while so I'm guessing it's a XF brain fart as you diagnosed. 3 more months of warranty left so I hope if anything bad is going to happen it happens now.

 

OOPS - noticed you have the 3.0 diesel - probably a whole different animal than the NA 5.0. Oh Well - xf brain fart just the same - lol